"The Shapemakers" consist of U.S. and Canadian aluminum extruder members of the Aluminum Extruders Council (AEC). The Shapemakers are the aluminum extrusion industry members who have united their efforts toward building awareness of the many applications of extruded aluminum as the preferred material over vinyl, steel, copper and composites in all major markets.

The Shapemakers of North America, on behalf of their industry, emphasize the value-added benefits of aluminum extrusion use over other materials and processes. These properties include strength, resiliency, durability, lightness, high strength-to-weight ratio, energy efficiency, and attractive finishes enhanced with painting or anodizing.

In addition, aluminum extrusions have value-added properties that make them flexible and adaptable components: corrosion-resistance, excellent heat and electrical conduction, wide market acceptance, reflectivity, nonsparking, non-magnetic, and noncombustibility, cold-resistant, seamless, joinable, recyclable, uniformity, ease of assembly, and cost effectiveness.

To assist in understanding the aluminum extrusion process, the Shapemakers explain some basic process principles:

Much like toothpaste is squeezed through a shaped nozzle from a tube, properly alloyed aluminum which has been carefully cast into softened billet is squeezed through a "container" to a precisely shaped die profile. The die serves as the "nozzle"--the aluminum billet's only way out.

Extrusion begins when a hydraulically powered ram forces the heated metal through the die. The number of tons of pressure the press exerts determines how large an extrusion it can produce. Extrusion size is measured by its longest cross sectional dimension--its fit within a circumscribing circle.

As pressure increases, the aluminum squeezes through the die opening, emerging on the other side as a fully shaped extrusion. The completed extrusion is then cut off at the die and quenched, mechanically adjusted and aged. The hardness of the alloy determines how fast it may be extruded through the press. Depending on billet size and die opening, a continuous extrusion up to 200 feet long may be produced in one press stroke.

Hollow shapes may also be extruded by projecting a mandrel into the core of the die opening, advancing inside the extruded metal from the ram through the dummy block and billet, or projected through a hollow ram while the mandrel remains stationary. Thus, metal flow is uninterrupted, resulting in a product with uniform grain structure and low residual stress level differences. Most hollow extrusions are made with spider dies, porthole dies or bridge dies.

The applications of aluminum extrusions are as varied and unlimited as the imagination can form. Precise shapes and characteristics for an intended purpose can be designed and manufactured from simple to complex shapes. Examples include:

• Solid shapes: tie-down plates for a trailer or a mini-finned head for a radial motorcycle engine.

• Semihollow and hollow shapes for an emergency vehicle toplight base, for framing, floor supports, fence posts, beams or door frames, round tubing for outdoor furniture, roadway barriers or bridge parapets.

• Elongated or short parts sliced from lengthy extrusions.

• Self-assembled, interlocking or hinged parts-bumpers and "skeletons" for trucks or cars, optical bar code scanners, cabinet covers, lighting fixtures and other modular assemblies.

• High-finish, high-strength parts:
  • single-die extrusion design of modular assemblies yields significant economies in part production, fabrication, stock management, handling, and transportation.

  • multi-extrusion assembled (eccentric) mechanisms include two of each part.

  • extruded eccentrics with an ultra-high molecular weight polymer bearing require no machining and run for years without servicing or lubrication.

  • extruded aluminum structural beams with high strength- to-weight ratios are suitable for fixed and mobile structures, all-aluminum or shapes joined with a wooden core or insert to combine aluminum's advantages with the building/ construction advantages of wood (aluminum's lightness in this area plays a major role in speeding construction and reducing costs).

• High-precision parts:
  • a single piece anodized aluminum extrusion makes an attractive, high-tech speaker cabinet with walls only 3mm thick.

  • internally-grooved, extruded aluminum channels used to guide electronic circuit boards through production processes (the one-piece aluminum extruded frames maintain exceptionally close tolerances, rigidity and permanent alignment).

Freedom of choice is obviously a distinct advantage when designing with aluminum extrusions. Extrusions offer freedom from "standard" shape restrictions often found in traditional structural materials. Extruded aluminum parts serve the dual purpose of decoration and function. Many parts can be combined into one extrusion at low cost, compared with other tooling methods. Aluminum extrusions require far less lead time from design to production, compared to other material production processes, with only a few weeks to make production tooling.

End uses of North American Aluminum Extrusion Industry shipments constitute 52% for building and construction, 19% for transportation, 10% electrical, 9% consumer durables, 7% machinery and equipment, and 3% other uses (source: Aluminum Association).

Extruder capabilities cover a full range of services. Each extruder's equipment has a maximum "circle size" for hard and soft alloys. Extruders produce some or all of the following: solid shapes, hollow or semi-hollow shapes, rod/bar, tube, drawn tube or coil tube shapes.

Finishing services range from polishing/buffing, scratch brushing, barrel tumbling and embossing to vibratory finishing, etching bright dipping, anodizing, integral color or two-step anodizing, conversion coating, electrostatic painting, powder coating, fluorocarbon painting, and silk screening.

Fabricating services offered by aluminum extruders include; cut-to length, mitering, drilling, tapping, punching, milling, notching, bending, deburring, CNC machining, and non-skid surfacing.

Special services and forms offered by some extruders include: design assistance, welding, assembling, heat treating, miniature shapes, stepped shapes, extra thin shapes, prototypes, protective films, CAD, thermal barriers, and appliques.

All in all, function and design parameters determine the most suitable type of extrusion for a particular application. Designers need not compromise ideas and plans to accommodate the restrictions posed by a standard material or shape. Other materials may offer a few of aluminum extrusion's advantages, but not all at the same time.

The Shapemakers are able to work closely with customers to help reduce overall costs through engineering assistance, design suggestions, fabricating, finishing, and other value-added services. Aluminum extruders are "The Shapemakers" who strive to make innovations that will provide better quality products to industry.